METHOD AND A DEVICE FOR FINDING IMPERFECTIONS IN AN RF PATH

• US 20100081427A1
• Filed: 03/26/2007
• Published: 04/01/2010
• Est. Priority Date: 03/26/2007
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Boncz, Lars, Lennartson, Benny
• Granted Patent: US 8,811,928 B2
• Time in Patent Office: Days
• US Class Current: 455/424
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/0684 using different training sequences per antenna
• CPC Class Codes: H04B 7/0822 according to predefined selection scheme

Abstract

The invention discloses a method (700) for finding differences in path loss between a plurality of RF paths between a first (120, 130) and a second (120, 130) transceiver in a wireless communications system (100). During defined 5 intervals of time (SACCH1-SACCH4), only one RF path is used to transmit from one of said transceivers to the other of said transceivers, and the receiving transceiver measures the strength of the signal received during at least a number of said intervals, thus making it possible to compare signal strength and thereby path loss between different RF paths, which in turn 10 makes it possible to find imperfections in one or more of said RF paths.

Claims

1. A method for finding differences in path loss between a plurality of radio frequency (RF) paths between a first transceiver and a second transceiver in a wireless communications system, the method comprising:

using, during defined intervals of time, only one RF path to transmit from one of said transceivers to the other of said transceivers,

measuring a strength of a signal received during at least a number of said intervals,

comparing the signal strength and path loss between different RF paths, and

finding imperfections in one or more of said RF paths based on the comparing.

2. The method of claim 1, where said first transceiver is the transmitting transceiver during said intervals,

where the second transceiver is the receiving transceiver during said intervals, and

where the method further comprises:

sending, via the second transceiver, reports on said measurements to the first transceiver.

3. The method of claim 2, where the first transceiver and the second transceiver communicate with each other in specified data frames which have a certain extension in time,

where the second transceiver carries out the measurements of the received signal strength during at least a specified period of one of said data frames, and

where said intervals in which only one RF path is used at least in part coincide with the measurement periods of the second transceiver.

4. The method of claim 3, where the intervals that an RF path is used is a same as said period during which the second transceiver makes its measurements.

5. The method of claim 1, where said second transceiver is the transmitting transceiver during said intervals, and

where the first transceiver is the receiving transceiver during said intervals.

6. The method of claim 5, where the first transceiver and the second transceiver communicate with each other in specified data frames which have a certain extension in time,

where the first transceiver carries out measurements of the received signal strength during at least a specified period of one of said data frames, and

where said intervals in which only one RF path is used at least in part coincide with the measurement periods of the first transceiver.

7. The method of claim 6, where the intervals that an RF path is used is a same as said period during which the first transceiver makes its measurements.

11. The method of claim 1, where the comparing includes:

comparing the signal strength from two different intervals, said two intervals being from a same session between said two transceivers, where said two intervals are two consecutive intervals.

13. The method of claim 1, further comprising:

sending reports on the measurements to a third node in the wireless communications system, the reports allowing for the signal strengths to be compared and conclusions draw regarding the path losses between different RF paths.

14. The method of claim 1, further comprising:

compiling, via the first transceiver, reports on said measurements, the reports allowing conclusions to be drawn regarding the path losses between different RF paths.

8-10. -10. (canceled)

12. (canceled)

15. A transceiver for use in a wireless communications system, the transceiver comprising:

at least a first transmitter and a second transmitter, and

at least a first receiver and a second receiver, the at least the first transmitter and the second transmitter and the at least the first receiver and the second receiver being for communication with another transceiver in said wireless communications system, so that at least a first radio frequency (RF) path and a second RF path are available, in both the transmit and receive direction for said transceiver, for communication with a second transceiver in the wireless communications system,

where the transceiver further comprises;

means for switching between the first and second RF paths so that during defined intervals of time, only one RF path, of the first and second RF paths, is used for transmission or reception in the communication with said second transceiver in the wireless communications system.

16. The transceiver of claim 15, where the switching means enables the transceiver to only transmit on one RF path at a time during said intervals in time,

where the transceiver further comprises:

means for receiving measurement reports from the second transceiver on the signal strength for the RF paths used for transmission during said intervals.

17. The transceiver of claim 15, where the switching means enables the transceiver to only receive on one RF path at a time during said intervals in time,

where the transceiver further comprises:

means for compiling measurement reports on signal strength of the RF paths used for transmission.

18. The transceiver of claim 16, further comprising:

means for evaluating said reports to identify differences in RF path loss.

19. The transceiver of claim 16, further comprising:

means for transmitting said reports to a third node in the wireless communications system.

20-22. -22. (canceled)